1. Field of the Invention
The present invention relates to an anisotropic conductive member and a multilayer wiring substrate.
2. Description of the Related Art
A metal filled microstructure (device) that is obtained by filling micropores provided in an insulating base with a metal is one of the fields which have attracted attention in recent nanotechnologies. For example, it is expected that a metal filled microstructure will be used for an anisotropic conductive member.
An anisotropic conductive member is inserted between an electronic component such as a semiconductor element and a circuit board, and electrical connection is obtained between the electronic component and the circuit board by simply applying pressure to the anisotropic conductive member. Thus, an anisotropic conductive member is widely used, for example, as an electrical connection member for an electronic component such as a semiconductor element or as a connector for inspection in a functional test.
Particularly, downsizing of electronic components such as a semiconductor element remarkably occurs and since conventional methods such as wire bonding in which wiring substrates are directly connected, flip chip bonding, and thermocompression bonding cannot secure sufficient connection stability, an anisotropic conductive member is attracting attention as an electronic connection member.
As a microstructure which can be used for an anisotropic conductive member, for example, JP2010-067589A discloses a “microstructure including an insulating base having micropore through holes having an opening diameter of 10 to 500 nm at a density of 1×106 to 1×1010/mm2, in which the micropore through holes are filled with a metal at a filling rate of 30% or more, and a layer made of a polymer is provided on at least one surface of the insulating base” ([Claim 1]).